Existing products, which take the n-type metal oxide semiconductor (nMOS) low temperature polysilicon-liquid crystal display (LTPS-LCD) as an example, are usually manufactured by adopting 9 patterning processes. Generally, before an active layer is formed, a light shield layer is formed on a base substrate by using a metal material such as molybdenum. In prior art, the light shield layer is formed by patterning a metal layer which is formed on an entire surface of the base substrate. However, forming the metal layer on the entire surface of the base substrate may easily cause an abnormal discharge phenomenon.